Internal Frames problem

Question

Hi,
I am writing a piece of code where I want to able to choose from a menu a screen that displays multiple graphs (using Internal frames.) I am using cardlayout to bring up the various options I choose from the menu. I have simplified my program as much as possible but I still seem to be getting the same error
Exception in thread "main" java.lang.IllegalArgumentException: adding a window to a container .......
I know I shouldn't be adding a window to a container but I can't see how I can change my code so it has the functionality I desire.
Here is the code I am using
import java.awt.*;
import javax.swing.*;
public class Test extends JFrame
     public Test()
         JPanel card1 = new JPanel();
         card1.add(new InternalFrameDemo());
          getContentPane().add(card1);
    public static void main(String[] args)
          Test frame = new Test();
          frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
          frame.setSize(200, 200);
          frame.setLocationRelativeTo( null );
          frame.setVisible(true);
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class InternalFrameDemo extends JFrame
    JDesktopPane desktop;
    static final int xOffset = 30, yOffset = 30;
    private JLabel graph1;
    private String Graph1;
    public InternalFrameDemo() {
        super("InternalFrameDemo");
        //Make the big window be indented 50 pixels from each edge
        //of the screen.
        int inset = 50;
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        setBounds(inset, inset,
                  screenSize.width  - inset*2,
                  screenSize.height - inset*2);
        //Set up the GUI.
        desktop = new JDesktopPane(); //a specialized layered pane
        createFrame(); //create first "window"
        setContentPane(desktop);
        //Make dragging a little faster but perhaps uglier.
        desktop.setDragMode(JDesktopPane.OUTLINE_DRAG_MODE);
    //Create a new internal frame.
    protected void createFrame() {
        MyInternalFrame frame = new MyInternalFrame();
        frame.setVisible(true);
        desktop.add(frame);
        try {
            frame.setSelected(true);
        } catch (java.beans.PropertyVetoException e) {}
    //Quit the application.
    protected void quit() {
        System.exit(0);
   public void MyInternalFrame() {
     System.out.println("graph1");
     graph1 = new JLabel("", 
                   new ImageIcon("../images/Graph1.jpg"),
                   JLabel.CENTER);
     getContentPane().add(graph1);
     //...Then set the window size or call pack...
     setSize(500,550);
}If anyone could point me in the right direction it would be great. Thanks in advance!

Answer 1

But I actually do not understand what that card layout thing is all about. If you want to hide/show internal frames you can simply use setVisible() and setSelected() like examplified below (I did put all code in the same file for my convenince). I have put a text in the label so that you can see that it is replaced. Using aJLabel to show an image is however a little bit weird.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
class MyInternalFrame extends JInternalFrame
  private JLabel graph1;
  public MyInternalFrame(String text)
    graph1 = new JLabel(text, 
                        new ImageIcon("../images/Graph1.jpg"),
                        JLabel.CENTER);
    getContentPane().add(graph1);
    setSize(500,550);
public class InternalFrameDemo extends JFrame
  private JDesktopPane desktop;
  private final MyInternalFrame[] frames;
  public InternalFrameDemo()
    super("InternalFrameDemo");
    frames = new MyInternalFrame[3];
    //Make the big window be indented 50 pixels from each edge of the screen.
    int inset = 50;
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    setBounds(inset, inset,
              screenSize.width  - inset*2,
              screenSize.height - inset*2);
    //Set up the GUI.
    desktop = new JDesktopPane(); //a specialized layered pane
    setContentPane(desktop);
    frames[0] = createFrame("Hello world!");
    frames[1] = createFrame("Hello again, world!");
    frames[2] = createFrame("Goodbye cruel world!");
    desktop.setDragMode(JDesktopPane.OUTLINE_DRAG_MODE);
    setSize(500, 500);
    Thread animThread = new Thread()
        public void run()
          for (int i = 0; i < frames.length; ++i)
            final int frameId = i;
            SwingUtilities.invokeLater(new Runnable()
                public void run()
                  // Hide frame that is showing.
                  if (frameId != 0)
                    frames[frameId - 1].setVisible(false);
                  System.out.println("Replacing image: " + frameId);
                  frames[frameId].setVisible(true);
                  try
                    frames[frameId].setSelected(true);
                  catch (java.beans.PropertyVetoException exc)
                    exc.printStackTrace();
            try
              Thread.sleep(3000);
            catch (InterruptedException exc)
              exc.printStackTrace();
    animThread.start();
  //Create a new internal frame.
  protected MyInternalFrame createFrame(String text)
    MyInternalFrame frame = new MyInternalFrame(text);
    desktop.add(frame);
    return frame;
  public static void main(String[] args)
    JFrame frame = new InternalFrameDemo();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
}Using lazy initialization where you postpone the creation of an internal frame until it is actually shown would be an improvement.
The setVisible/Selected() call can of course be triggered by something else in your application.
Note that changes of swing components shall be made in the EDT.